diff --git a/src/linter/ui5Types/SourceFileLinter.ts b/src/linter/ui5Types/SourceFileLinter.ts
index ca567596..6cd520ef 100644
--- a/src/linter/ui5Types/SourceFileLinter.ts
+++ b/src/linter/ui5Types/SourceFileLinter.ts
@@ -46,7 +46,7 @@ export default class SourceFileLinter {
 		context: LinterContext, resourcePath: ResourcePath,
 		sourceFile: ts.SourceFile, sourceMap: string | undefined, checker: ts.TypeChecker,
 		reportCoverage: boolean | undefined = false, messageDetails: boolean | undefined = false,
-		dataTypes: Record<string, string> | undefined, manifestContent?: string | undefined
+		dataTypes: Record<string, string> | undefined, manifestContent?: string
 	) {
 		this.#resourcePath = resourcePath;
 		this.#sourceFile = sourceFile;
diff --git a/test/lib/linter/_linterHelper.ts b/test/lib/linter/_linterHelper.ts
index 6b82d01c..42e61cf5 100644
--- a/test/lib/linter/_linterHelper.ts
+++ b/test/lib/linter/_linterHelper.ts
@@ -31,7 +31,7 @@ export async function esmockDeprecationText() {
 				reportCoverage: boolean | undefined = false,
 				messageDetails: boolean | undefined = false,
 				dataTypes: Record<string, string>,
-				manifestContent?: string | undefined
+				manifestContent?: string
 			) {
 				// Don't use sinon's stubs as it's hard to clean after them in this case and it leaks memory.
 				const linter = new SourceFileLinter(